Both incidents occurred while vessels were attempting to cross the bar at the entrance to Tairua Harbour yesterday morning. There was a level two “take care” warning on the bar at the time.

In the first incident, a man broke his leg when a large wave picked up a boat carrying three people and smashed it back down. The boat remained floating but the man had to be taken to hospital.

In the second incident, a man’s boat capsized and had to be retrieved by the Coastguard. The man was not injured.

“Bars always needed to be treated with caution because conditions can change very quickly – just because one bar crossing went well doesn’t mean the next one will,” Mr Pearks said.

“If skippers don’t check the weather conditions and bar warnings before going out, they could be putting lives at risk. There have been some serious injuries from bar accidents in our region this summer and one man could have died.

“If you have any questions or need any information about bar crossings, please call your local Environment Waikato harbourmaster on 0800 800 401.”

Bars are underwater hills formed by mud and sediment washing into the sea from rivers. As waves or swells move in from the sea, the rapidly rising sea bed causes them to break suddenly, creating a potentially dangerous situation for any vessel crossing them. A bar can change shape within a day.

In the Waikato region, west coast bars are even more hazardous, because harbours are larger and there is more water moving in and out, the bars tend to be further out to sea and swells are larger.